As wireless computing and distributed sensor networks become more mature and widespread, a bottleneck for the technology deployment becomes the power source. Conventionally, a wireless, portable sensor or microprocessor is powered by a battery. Though battery technologies have improved, energy densities and lifetimes are still issues for many systems. A battery holds a finite amount of energy; when that energy has been used by its load, the battery must be recharged. For many remote systems, recharging a battery is not an option. If a system is required to remain idle for months or years and then spring to life at a certain moment, a battery may have been depleted already due to leakage or self-discharge. Finally, batteries often involve chemicals which are harmful to humans and to the environment. The present invention provides a solution to these problems in the form of an energy harvesting device for supplying power to (inter alia) small remote systems and conversely as a sensor for sensing vibrations in its environment and generating an electrical signal in response thereto. Applications where harvesting or sensing vibrations can be desired include; air, water and land-based vehicles, oil rigs, heavy machinery, bridges and other architectural structures subjected to vibrations. The terms “vibration sensing device”, “vibrational energy converter”, “vibrational energy harvester”, “energy harvester”, and “mechanical vibration to electrical energy converter” are interchangeable in the context of this specification.